Lymphocyte Nadir and Esophageal Cancer Survival Outcomes Following Chemoradiotherapy
Menée à partir de données portant sur 504 patients atteints d'un cancer de l'œsophage de stade I à III traité entre 2007 et 2013 par chimioradiothérapie néoadjuvante ou définitive (durée médiane de suivi : 36 mois), cette étude évalue l'association entre le niveau le plus bas de lymphocytes durant le traitement et la survie des patients
Purpose : Host immunity may affect the outcome of esophageal cancer patients. We sought to identify factors that influenced absolute lymphocyte count (ALC) nadir during chemoradiation therapy (CRT) for esophageal cancer (EC) and looked for clinically relevant associations with survival.
Materials/Methods : 504 patients with stage I-III EC (2007–2013) treated with neoadjuvant or definitive CRT with weekly ALC taken during treatment were analyzed. Grade of lymphopenia from ALC nadir during CRT was based on CTCAE v4.0. Associations of ALC nadir with survival were examined using multivariate Cox proportional hazards analysis (MVA) and competing risks regression analysis.
Results : The median follow-up time was 36 months. Incidence of grade 1, 2, 3, and 4 ALC nadir during CRT were 2%, 12%, 59% and 27%, respectively. Impact was lymphocyte-specific as this was not seen for monocyte or neutrophil count. On MVA, grade 4 ALC nadir (G4 nadir) was significantly associated with worse overall and disease-specific survival outcomes. Predictors of G4 nadir included distal tumor location, definitive CRT, taxane/5FU chemotherapy, and photon-based radiation type (vs. proton-based). Radiation type strongly influenced the mean body dose (MBD) exposure, which was a strong predictor for G4 nadir (OR 1.22 per Gray, p<0.001).
Conclusions : G4 nadir during CRT for EC was associated with poor outcomes suggesting a role of host immunity in disease control. This observation provides a rationale to prospectively test chemotherapeutic and radiation treatment strategies that may have a lower impact on host immunity.
International Journal of Radiation Oncology • Biology • Physics , résumé, 2016